1. Field of the Invention
The invention relates to a screw for joining thin workpieces, with a shank and a washer-like head provided with a tool drive, wherein the shank is provided with a thread and at its free end remote from the head has a hole-forming or hole-boring point, and wherein the head, measured in the axial direction of the screw, has a height which is smaller than twice the pitch of the thread formed on the shank.
2. Description of the Related Art
Self-boring and self-tapping screws are usually used precisely for mutual fastening of relatively thin materials or for fastening of thin materials to a fixed substructure, while for technical reasons it is not possible to use countersunk head screws, because an appropriate recess cannot also be formed simultaneously in a workpiece in a single boring and driving process. If a lining element such as a plate is to be subsequently attached in this fastening region, either a corresponding countersunk opening must be made beforehand or screw heads with correspondingly large height must be tolerated, even though they do not allow subsequently mounted plates to rest almost flat on the substructure over a large area.
The object of the present invention is therefore to provide a screw of the type mentioned in the introduction, with which there can be achieved secure fastening in which the screw is not weakened by a socket drive and a sound joint is not prevented by stripping of the thread.